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Site-selective modification of oligonucleotides serves as an indispensable tool in many fields of research including research of fundamental biological processes, biotechnology, and nanotechnology. Here we report chemo- and regioselective modification of oligonucleotides based on rhodium(I)-carbene catalysis in a programmable fashion. Extensive screening identifies a rhodium(I)-catalyst that displays robust chemoselectivity toward base-unpaired guanosines in single and double-strand oligonucleotides with structurally complex secondary structures. Moreover, high regioselectivity among multiple guanosines in a substrate is achieved by introducing guanosine-bulge loops in a duplex. This approach allows the introduction of multiple unique functional handles in an iterative fashion, the utility of which is exemplified in DNA-protein cross-linking in cell lysates. The methods for investigation of DNA-binding proteins require site-selective chemical modifications to be introduced into oligonucleotides. Here, the authors report a chemo- and regioselective method for the modification of unpaired guanosines in single- and double-stranded oligonucleotides, based on Rh(I)-carbene catalysis. [ABSTRACT FROM AUTHOR]

UV-activated alkyne–alkene [2 + 2] cycloaddition has served as an important tool to access cyclobutenes. Although broadly adopted, the limitations with UV light as an energy source prompted us to explore an alternative method. Here we report alkyne–alkene [2 + 2] cycloaddition based on visible light photocatalysis allowing the synthesis of diverse cyclobutenes and 1,3-dienes via inter- and intramolecular reactions. Extensive mechanistic studies suggest that the localized spin densities at sp2 carbons of alkenes account for the productive sensitization of alkenes despite their similar triplet levels of alkenes and alkynes. Moreover, the efficient formation of 1,3-dienes via tandem triplet activation of the resulting cyclobutenes is observed when intramolecular enyne cycloaddition is performed, which may serve as a complementary means to the Ru(II)-catalyzed enyne metathesis. In addition, the utility of the [2 + 2] cycloaddition has been demonstrated by several synthetic transformations including synthesis of various extended π-systems. [2 + 2] cycloaddition of alkynes with alkenes would normally require UV light irradiation. Here, the authors report an alkyne–alkene [2 + 2] cycloaddition based on visible light energy transfer photocatalysis, both inter- and intramolecularly, to afford cyclobutenes and 1,3-dienes. [ABSTRACT FROM AUTHOR]

Sphingosine kinase1 (SphK1) is an acetyl-CoA dependent acetyltransferase which acts on cyclooxygenase2 (COX2) in neurons in a model of Alzheimer's disease (AD). However, the mechanism underlying this activity was unexplored. Here we show that N-acetyl sphingosine (N-AS) is first generated by acetyl-CoA and sphingosine through SphK1. N-AS then acetylates serine 565 (S565) of COX2, and the N-AS-acetylated COX2 induces the production of specialized pro-resolving mediators (SPMs). In a mouse model of AD, microglia show a reduction in N-AS generation, leading to decreased acetyl-S565 COX2 and SPM production. Treatment with N-AS increases acetylated COX2 and N-AS-triggered SPMs in microglia of AD mice, leading to resolution of neuroinflammation, an increase in microglial phagocytosis, and improved memory. Taken together, these results identify a role of N-AS in the dysfunction of microglia in AD. Neuronal sphingosine kinase 1 (SphK1) acetylates COX2 which is needed for microglial phagocytosis activity, and release of pro-resolving mediators (SPMs) from neurons. Here the authors examine how SphK1-mediates COX2 acetylation, and how this leads to increased secretion of SPMs from neurons in the context of Alzheimer's disease models. [ABSTRACT FROM AUTHOR]

Objectives: Second shot arterial phase (SSAP) imaging is an additional arterial phase image obtained by re-injecting a small amount of contrast medium after routine dynamic imaging in gadoxetic acid-enhanced liver MRI. We aimed to evaluate the feasibility and additional value of a SSAP image in gadoxetic acid-enhanced liver MRI.Methods: One hundred seventy-two patients who underwent SSAP imaging after re-injection of 4 mL of contrast material after routine dynamic imaging (original) in gadoxetic acid-enhanced liver MRIs were included. Motion artifacts on arterial phase (AP) images were rated using a 5-point scale and were compared between the original AP images and SSAP images. We evaluated visual detection rates of arterial hypervascularity on the original AP and SSAP images and their subtraction images in patients with hypervascular hepatocellular carcinoma (HCC).Results: The motion artifact of the SSAP images was significantly lower than that of the original AP images (mean score, 1.76 vs 2.06; p < 0.001). In particular, motion artifacts reduced significantly in the SSAP images of patients with substantial motion artifacts in their original AP images (2.28 vs 3.28; p < 0.001). Among the 30 HCC lesions showing hypervascularity on original AP images, only four (4/30, 13.3%) appeared hyperintense on SSAP images. However, subtraction images of SSAP clearly demonstrated arterial hypervascularity in all HCCs.Conclusion: SSAP images showed significantly fewer motion artifacts than the original AP images. Subtraction images of SSAP maintained the detectability of arterial hypervascularity, although SSAP images showed poor visual detection of arterial hypervascularity of HCC.Key Points: • Arterial phase images obtained after a second injection of a small amount of contrast medium (second shot arterial phase [SSAP]) improved motion artifacts compared to the original AP images. • The motion artifacts improved significantly in the SSAP images of patients with substantial motion artifacts in their original AP images. • Subtraction images of SSAP demonstrated the arterial hypervascularity characteristic of HCC at a level comparable to that of the original AP image. [ABSTRACT FROM AUTHOR]

Antimony selenide and its carbon composite were synthesized through a mechanochemical process and investigated as anode materials for sodium-ion secondary batteries. X-ray diffraction (XRD) with rietveld refinement and transmission electron microscopy (TEM) analyses confirm that Sb2Se3 were composed of agglomerated highly crystalline nanocrystallites and the Sb2Se3/C composite consisted of nanocrystalline Sb2Se3 dispersed homogeneously throughout an amorphized carbon matrix. The initial Coulombic efficiency, rate capability, and cycle performance of the Sb2Se3/C composite were superior to those of Sb, or Sb2Se3. The Sb2Se3/C composite, in particular, showed excellent cycle stability, with 98.2% of initial capacity at 200 mA g−1 after 200 cycles. Based on the reaction potentials, ex situ XRD patterns and ex situ HR-TEM analysis of the Sb2Se3/C composite electrode revealed the structural changes which occurred reversibly within the Sb2Se3/C composite by conversion and recombination reaction during sodiation and desodiation process. Furthermore, XPS analysis study was carried out for identifying the surface films formed on both the electrodes and their effects on the performances.Graphical abstract: [ABSTRACT FROM AUTHOR]

Objectives: To compare the diffusion parameters of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) between the "reflux" and the "non-reflux" kidneys, and to evaluate the feasibility of using IVIM DWI to predict vesicoureteral reflux (VUR) in children with a urinary tract infection (UTI).Methods: Eighty-three kidneys from 57 pediatric patients with a UTI were classified into "reflux" and "non-reflux" groups according to voiding cystourethrography (VCUG) results. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (PF) were measured and compared in the renal pelvis of both groups. Four indices (D*/ADC, PF/ADC, D*/D, and PF/D) were calculated and receiver operating characteristic (ROC) curve analyses were performed.Results: VURs were detected on VCUG in 21 kidneys. PF and D* were significantly higher in the "reflux" group than in the "non-reflux" group. The indices were all significantly higher. The PF/D index showed the best diagnostic performance in predicting VUR in children with UTI (Az = 0.864).Conclusion: PF and D* were significantly higher in the "reflux" kidney than in the "non-reflux" kidney. Our new index (PF/D) could prove useful for predicting VUR.Key Points: • IVIM DWI is both radiation-free and contrast media-free. • IVIM DWI index is easily calculated by combining diffusion parameters. • IVIM DWI may help predict VUR in children with UTI. • PF is significantly higher in the "reflux" than the "non-reflux" kidneys. • A new VUR index, PF/D could prove useful for predicting VUR. [ABSTRACT FROM AUTHOR]

To investigate the electrochemical reaction mechanism of As, which shows poor electrochemical reversibility with Li, an As/C nanocomposite was prepared using a straightforward high-energy mechanical milling technique. The electrochemical reaction mechanism of the As/C nanocomposite electrode with Li was elucidated by ex situ XRD and HRTEM analyses in combination with differential capacity plot analysis. Electrochemical tests showed that the As/C nanocomposite exhibited good reversibility between the LiAs (0.85 V) and As (2 V) phases showing quasi-intercalation reaction. [ABSTRACT FROM AUTHOR]

We define a polynomial generating pairing (PGP) and propose a method to construct a family of pairing friendly curves from PGP. We show that a bilinear map over the family is directly determined by the coefficients of the PGP and the map is non-degenerate under a minor condition which is satisfied with cryptographic parameters. Finally, we provide a criterion for PGP to obtain an optimal pairing. [ABSTRACT FROM AUTHOR]

We provide a simple and exact formula for the minimum Miller loop length in Ate pairing based on Brezing-Weng curves, in terms of the involved parameters, under a mild condition on the parameters. It will also be shown that almost all cryptographically useful/meaningful parameters satisfy the mild condition. Hence the simple and exact formula is valid for them. It will also turn out that the formula depends only on essentially two parameters, providing freedom to choose the other parameters to address the design issues other than minimizing the loop length. [ABSTRACT FROM AUTHOR]

Cobalt oxide-based nanocomposites are prepared using CoO, various metals (Al, Mg), carbon powders, and a simple high-energy mechanical milling technique. X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy show that the cobalt oxide-based composites are mainly composed of nanostructured CoO/AlO, CoO/MgO, and CoO/C composites, respectively. Based on concepts related to the enhanced electrical conductivity of the CoO/C nanocomposite using conducting carbon matrix and to the resistance of inactive ceramic matrices (AlO, MgO) against active CoO particle growth during cycling, various nanostructured cobalt oxide-based composites are tested for use as anode materials. Among the composites, the CoO/C nanocomposite anode exhibits good electrochemical characteristics, such as high-capacity, good initial Coulombic efficiency, and long cycle behavior for Li-ion batteries. [ABSTRACT FROM AUTHOR]

Vercauteren introduced the concept of optimal pairing, which by definition can be computed by using at most (log r)/ φ( k) + log k basic Miller iterations, where r is the order of the groups involved and k is the embedding degree Vercauteren (IEEE Trans Inf Theory 56(1):455-461, ). Freeman et al. summarized and proposed all of the new constructions of pairing-friendly elliptic curves that currently exist Freeman et al. (J Cryptol 23(2):224-280, ). In this paper, we give an optimal pairing for each family of pairing-friendly curves in Freeman et al. (J Cryptol 23(2):224-280, ) by taking the Ate or R-ate pairing approach. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) in an ectopic liver is very rare and its CT findings have never been reported. We present an ectopic HCC between the spleen and left diaphragm, mimicking a splenic neoplasm on the CT scan. A follow up CT at seven months postoperatively revealed multiple recurrent HCCs in the mother liver. [ABSTRACT FROM AUTHOR]

New battery systems having high energy density are actively being researched in order to satisfy the rapidly developing market for longer-lasting mobile electronics and hybrid electric vehicles. Here, we report a new Li-Te secondary battery system with a redox potential of ~1.7 V (vs. Li+/Li) adapted on a Li metal anode and an advanced Te/C nanocomposite cathode. Using a simple concept of transforming TeO2 into nanocrystalline Te by mechanical reduction, we designed an advanced, mechanically reduced Te/C nanocomposite electrode material with high energy density (initial discharge/charge: 1088/740 mA h cm−3), excellent cyclability (ca. 705 mA h cm−3 over 100 cycles), and fast rate capability (ca. 550 mA h cm−3 at 5C rate). The mechanically reduced Te/C nanocomposite electrodes were found to be suitable for use as either the cathode in Li-Te secondary batteries or a high-potential anode in rechargeable Li-ion batteries. We firmly believe that the mechanically reduced Te/C nanocomposite constitutes a breakthrough for the realization and mass production of excellent energy storage systems. [ABSTRACT FROM AUTHOR]